As China advances its national strategy for building a strong transportation nation, the requirements for subgrade stability and settlement control in high-speed railway operations have become increasingly stringent. In recent years, Professor Wang Lei’s research team at SUES has made significant progress in addressing the key issue of high embankment settlement in high-speed railways. Their work on the consolidation theory of unsaturated composite foundations provides critical theoretical support for the safe construction and operation of high-speed railways under complex geological conditions.
Traditional consolidation theories of composite foundations are generally based on the assumptions of saturated soils and uniformly distributed loads. However, in practical engineering—especially in arid or semi-arid regions—soils are often unsaturated, and loads induced by high embankments are locally non-uniform (see Figure 1).
Moreover, under the goal of “dual carbon”, minimizing material consumption while controlling subgrade settlement has become a key consideration in geotechnical engineering. Over the past decade, Professor Wang’s team has systematically tackled these challenges and successively developed consolidation theories for drained piles, undrained piles, and variable-section piles in unsaturated composite foundations. Their studies show that the settlement of saturated composite foundations is 30–50% higher and takes a longer time to stabilize than that of unsaturated ones (see Figure 2). Strengthening unsaturated composite foundations with variable-section piles significantly improves bearing capacity through soil–pile interaction, offering clear advantages in settlement control, economic efficiency, and environmental sustainability (see Figure 3).
Through persistent and rigorous research, Wang’s team has achieved a breakthrough in the consolidation theory of unsaturated composite foundations. To date, the group has received funding for one Postdoctoral Science Foundation project and three national-level research projects. They have published 25 SCI papers in Q1 and Q2 journals (including 2 ESI Highly Cited Papers) and won first prizes for scientific and technological progress at both provincial and national academic society levels. Looking ahead, supported by newly approved national projects, the team will continue to investigate the consolidation behavior of unsaturated layered composite foundations with variable-section piles under locally non-uniform loads, while incorporating pile deformation and pile–soil interaction effects. Their ongoing research will further bridge theory and engineering application, providing a robust scientific foundation for advancing China’s transportation modernization and achieving the “dual carbon” objectives.
Date: September 1st, 2025
Issued by: School of Urban Railway Transportation
